Background Info on Frame Rate. The term frame rate comes from the days of film cameras. When you took a photograph it would capture an image, but that image was only on the film for one thirtieth of a second, or 1/30th as they say. To show more than just single images on the film they created a projector that had two spinning reels, one with the film moving through it at 7 1/2 times per second, and another to show each frame on the screen at the same time. This allowed us to see motion with objects in an image instead of just a single photo.
The amount of images combined over one second was called the frame rate. For example, on a thirty second TV show, there are exactly 30 frames per second that all combine into the motion we see. The frame rate for video is no different than that of film with one exception. The frame rates used in the US and some other places around the world are 29.97 (actually rounded to 29.970010 for marketing), or 30. Usually when someone refers to frame rates they are referring to this 29.97 rate, but it is the same as 30 everywhere else in the world.
Interlacing – Before we go on any further, you need to understand Interlacing
Interlacing is used with all analog signals because there was no method of capturing digital information when the TV was first introduced. In order to create a full frame, two images are created and combined in a checkerboard pattern. To make it easy to understand lets say we have one full frame with all four corners filled equally from left to right top to bottom. On this one image you would have an even number of lines from top to bottom. Now say you want to view both images at the same time, for instance half the screen is one image and half is another (this is called interlacing). If you were looking at this on paper you would see a very clear picture with no problems. However, if you try and view both images rapidly one after the other you would start to see problems. The top half of the screen shows one image and the bottom two images show a different object than all four corners of the first image that was captured. The reason for this is that when we view these images rapidly one right after another there is not enough time for our brains to adjust and we notice the “tearing” and distraction of the lines. This is what Interlacing does, it takes two images and combines them into one to give us a full image instead of just single frames. For instance NTSC (North America) uses 30 interlaced fields per second while PAL (most of Europe and Asia) use 50 interlaced fields per second.
How to change aspect ratio in final cut pro
Ever wonder how to change aspect ratio in Final Cut Pro? Well, we finally have a solution for you. It’s super easy and very few things will be the same after you’ve done this!
STEP 1: Open up your photo browser and select your clip that you want to add different aspect ratios too.
STEP 3: Split the clip in your timeline by holding down “option” and click on the middle of the clip.
STEP 4: Go to edit -> insert into -> aspect ratio. Choose which one you want to bring up!
NOTE: If you are looking for a specific speed in your film, chances are you will need to create additional frames with different camera angles so that it is played back in the correct speed. When you change your frame rate, you are essentially finding a number of frames per second where the motion appears smooth for all objects in the scene. The more frames per second added or removed, the smoother your video becomes up until about 24 fps, then it starts to degrade.
Conclusion
Interlacing is used with all analog signals because there was no method of capturing digital information when the TV was first introduced. In order to create a full frame, two images are created and combined in a checkerboard pattern. For example NTSC (North America) uses 30 interlaced fields per second while PAL (most of Europe and Asia) use 50 interlaced fields per second.